An evaluation of mineral metabolism was performed in 41 patients with RA and the pertinent data were compared to bone mineral content in patients either untreated or treated with different doses of corticosteroids. Our study confirms that osteoporosis is a common finding even in rheumatoid patients never treated with corticosteroids. Moreover, in patients treated with such drug the loss of bone mineral content was related to the dosage rather than to the length of treatment. In all cases no overt biochemical derangement was observed. According to our study, parathyroid hormone does not seem to influence the development of osteoporosis in rheumatoid arthritis, while a relative deficiency of calcitonin along with an inadequate vitamin D metabolism could play some role.